Cleaning installation for heatexchangers



Nov. 2, 1965 w. TREPLIN "3,215,195

CLEANING INSTALLATION FOR HEAT-EXCHANGERS Filed March 6. 1963 2 Sheets-Sheet 1 INVENTOR- FRIEDRICH-WILHELM TREPLIN BY mm ATTORNEYS Nov. 2, 1965 I F. w. TREPLIN 3,215,195

CLEANING INSTALLATION FOR HEAT-EXGflANGERS 2 Sheets-Sheet 2 Filed March 6. 1963 FIG. 2

INVENTOR. FRIEDRICH-WiLHELM TREPLIN A TTORNEY United States Patent many Filed Mar. 6, 1263, Ser. No. 263,283 Claims priority, application Germany, Mar. 14, 1962,

6 tClaims. (a. 165-95) The present invention relates to a method for circulating cleaning bodies used in connection with cleaning tubetype heat exchangers as well as to the apparatus suitable for use in carrying out the method. More particularly, the present invention relates to a method and apparatus for intercepting and re-circulating the elastic cleaning bodies which are used for cleaning the pipes or tubes of heat exchangers, especially condensers, and which are circulated by means of the cooling Water from the cooling water inlet, through the heat exchanger, the cooling water outlet and a connecting line from the cooling water outlet to the cooling water inlet.

For purposes of cleaning heat-exchangers, especially condensers of power plants and the like, a method of cleaning the condenser pipes has become known in the prior art that has also proved of practical usefulness according to which cleaning bodies, preferably elastic cleaning bodies having the specific weight of the cooling water are added to the cooling water and are guided together with and carried by the cooling water through the condenser pipes or are pressed through the condenser pipes by the cooling water. The discharged cooling water thereby takes along these cleaning bodies and passes through sieve installations which intercept the cleaning bodies. The cleaning bodies intercepted by the sieve installations are thereupon returned by way of connecting lines between the cooling water inlet and the cooling water outlet and are re-introduced into the cooling Water inlet together with a partial stream of the heated cooling water by means of separate pumps. The US. Patents Nos. 2,801,824 and 3,021,117 to L. Taprogge are representative of such prior art arrangements.

The measures disclosed in both of these patents have proved themselves exceedingly well from a strictly cleaning point of view, however, they are disadvantageous from a thermodynamic point of view as a certain quantity of water is necessary for the return of the cleaning bodies which cannot be chosen suitably small since a certain minimum cross section has to be present at the discharge of the sieve installations for constructional reasons while simultaneously therewith a minimum velocity in this cross section. The heated partial stream of the discharged cooling water obviously impairs and reduces, by reasons of its temperature, the heat-exchanger efiiciency since the cooling Water inlet temperature into the condenser is increased thereby. This is particularly noticeable with relatively small condensers and heat exchangers having only small cooling water quantities.

It also happens frequently in both the chemical industry and power plants that several small heat-exchangers of differing dimensions which are connected with the same cooling water network are to be cleaned simultaneously. By reason of the differing construction of the heat-exchangers, cleaning bodies of differing quality have to be used which leads to the disadvantage that with the return systems used heretofore a separate return pump had to be utilized for each heat-exchanger.

The present invention aims at realizing a return system for the cleaning bodies in a cleaning system for tubetype heat-exchangers, and especially of condensers, by

Patented Nov. 2, 1965 means of cleaning bodies carried within the circulatory system from the cooling water inlet through the heatexchanger to the cooling water outlet without thermodynamic disadvantages as well as at a simplification of such return system.

The present invention is concerned with a method and apparatus for returning the cleaning bodies in connection with the cleaning operation of tube-type heat-exchangers, especially condensers, by means of cleaning bodies conducted in the water circulation by way of the cooling water inlet, the heat-exchanger, the cooling water outlet and a connecting line.

The present invention essentially consists in conducting the cleaning bodies intercepted in the usual manner by means of a sieve installation within the cooling water outlet into a sluice and to collect the same therein as well as to discontinuously return the cleaning bodies from the sluice into the cooling water inlet by means of cold water. A preferred embodiment according to the present invention is thereby characterized by the fact that the cleaning bodies intercepted in the sieve installation are introduced into the sluice by the flow energy of the discharged cooling water. Such an arrangement may be realized structurally in different ways. In the event that the cleaning system utilizes a sieve box and a sieve installation arranged therein for the interception of the cleaning bodies as is usual with the known cleaning methods, this may be attained, for example, by means of a damming-up chamber connected behind the sieve installation and by means of a by-pass line leading from the damming-up chamber by way of a sluice provided with a sieve basket back into the sieve box or back into the discharge or out let line. This arrangement is made simple from an operational point of view by arranging valves in the cold water line and in the by-pass line ahead of and behind the sluice, and by thus enabling the introduction through these valves and connecting lines, While shutting-off the by-pass lines, of cold water under pressure into the sieve basket of the sluice and thereby causing the cleaning bodies to be pressed into the cooling water inlet line. For purposes of supplying the cold water under pressure oftentimes the pressure of the system of the water supply network is sufficient. However, a pump for increasing the pressure may also be provided which withdraws cooling water from the cooling water inlet and forces the cooling water back into the cooling water by way of the sluice. With individual heat-exchangers the water under pressure may also be withdrawn out of the cooling water line ahead of a throttling device and the balls or friction bodies may be re-introduced into the line behind the throttling device. Additionally, under favorable circumstances the water under pressure may be taken from the pressure line of the cooling water pump and the cleaning bodies may be introduced into the suction line.

The advantages obtainable with the present invention reside above all in the fact that with the method and apparatus in accordance with the present invention the return of the cleaning bodies does not take place by means of heated cooling water but instead with cold water, preferably cold cooling water so that with such a return of the cleaning bodies the thermodynamic efficiency of the heat-exchanger is in no way impaired.

Additionally, the apparatus according to the present invention excels by its simplicity and safety as well as reliability in operation.

Accordingly, it is an object of the present invention to provide a circulatory system for the cleaning or friction bodies used to clean the pipes or tubes of heat-exchangers which, by simple means, avoids the aforementioned drawbacks and shortcomings encountered with the prior art systems.

It is another object of the present invention to provide a return system for returning the cleaning bodies, used in the self-cleaning installation of heat-exchangers, from the cooling water or discharge line to the cooling water inlet line without impairing the thermodynamic efliciency of the heat-exchanger.

Still another object of the present invention residesan the provision of a return system for the cleaning bodies of self-cleaning installations used with heat exchangers which improves the thermodynamic efliciency, especially with relatively small heat-exchangers or heat-exchangers utilizing only relatively small cooling water quanuties without concern for any minimum cross section or minimum velocity of the cooling water in the discharge line of the heat-exchanger.

Still a further object of the present invention resides in the provision of a return system for returning the cleaning bodies from the cooling water discharge line of the heat exchanger to the inlet line thereof which obviates the need for a separate return pump for each heat-exchanger in an arrangement in which several heat-exchangers are connected with the same cooling water network.

Another object of the present invention resides in the provision of a greatly simplified method of returning the cleaning bodies from the cooling water discharge line to the cooling water inlet line by means of which only relatively cool water is utilized to reintroduce the cleaning bodies into the cooling water inlet line of the heatexchanger.

These and other objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, one embodiment in accordance with the present invention and wherein:

FIGURE 1 is a somewhat schematic view of a selfcleaning installation for a heat-exchanger provided with an apparatus for realizing the method of returning the cleaning bodies in accordance with the present invention, and

FIGURE 2 is a partial cross sectional view, on an enlarged scale, through the sluice and valve subassembly for realizing the method of the present invention with a system illustrated in FIGURE 1.

Referring now to the drawing wherein like reference numerals are used throughout the two views to designate like parts, the heat-exchanger illustrated in FIGURE 1 is a tube-type or pipe heat-exchanger, for example, the con-denser of a steam power plant which is acted upon by cooling water. The cooling water enters into the condenser 2 through the cooling water inlet line 1 and leaves the condenser 2 through the discharge or outlet line 3. The heat-exchanging medium thereby flows transversely with respect to and on the outside of the pipes 4 of the condenser or heat-exchanger 2. For purposes of cleaning the heat-exchanger 2, cleaning bodies 5 are introduced into the cooling water circulatory system which are conducted through the pipes 4 by the cooling water, fulffill thereat the cleaning function, and are intercepted again in the cooling water outlet or discharge line 3 with the aid of a sieve assembly generally designate-d by reference numeral 6 as well as are returned from the sieve assembly 6 into the cooling water inlet line 1. The sieve installations 6 consist in the illustrated embodiment of two upper sieve portions 6a and 611 by means of which the cleaning bodies 5 are conducted or guided into a funnel portion 7 disposed therebelow which effectively forms a dammingup chamber or weir box. The lateral walls of this damming-up chamber 7 may be provided with outlet or discharge apertures, however, the conditions are usually so selected in accordance with well-known hydraulic principles that a genuine damming effect occurs. A sluice 9 provided with a sieve basket 10 is operatively connected by way of line 8 with the damming-up chamber 7. The sluice 9 in turn is connected again by way of a return line 11 with the sieve assembly 6. However. it is also understood that instead of discharging into the sieve assembly 6, the line 11 according to a modification of the present invention may also discharge into the outlet line or discharge line connected to the sieve assembly 6. The present invention thus comprises a damming chamber 7 connected behind the sieves 6a and 6b in combination with by-pass lines 8 and 11 extending from the damming-up chamber 7 to the sluice 9, itself provided with a sieve basket 10, and from the sluice 9 back into the sieve assembly 6 or into the discharge line, respectively. The cleaning bodies 5 are intercepted by the sieves 6a and 6b and reach by way of the damming-up chamber 7 and the section 8 of the by-pass line the sluice 9 where they retained by the sieve basket 19. The cooling water alone then returns from sluice 9 by way of the section 11 of the by-pass line into the discharge line. The valves 12 in the bypass line sections 8 and 11 and the valves 13 in the cooling water line sections 15 and 16 have thereby the position shown in FIGURE 1. When a sufficient number of cleaning bodies 5 have been collected in the sieve basket 10, then at first the valves 12 are actuated followed by an actuation of the valves 13. Both valve groups 12 and 13 are rotated for purposes of actuation by about Additionally, the pressure-increase pump 14 is engaged which may take place automatically with rotation of valves 13 which sucks cooling water out of the cooling water inlet line 1 by way of line section 15 and forces the cooling water into the inside of the sieve basket 10. The cleaning bodies 5 are then returned by means of the water under pressure by way of line section 16 into the cooling water inlet line 1 where, for purposes of improved random distribution, they are injected into the cooling water stream in counter flow. Consequently, the present invention achieves to reintroduce the cleaning bodies by means of cold water into the cooling water inlet line 1 so that during the cleaning operations the efiiciency of the heat-exchangers is not affected in any manner.

FIGURE 2 is an enlarged partial cross sectional view illustrating the sluice and valve assembly consisting of sluice 9, sluice basket 10 and valves 12 and 13 utilized in the arrangement of FIGURE 1. Since the details of FIGURE 2 are believed obvious particularly when taken together with the description of FIGURE 1, a detailed description of FIGURE 2 is dispensed with herein.

While I have shown and described one embodiment in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications within the spirit and scope thereof; for instance, any suitable semi-automatic electric control mechanism may be used for sequentially first closing valves 13 and thereafter re-opening valves 12. Additionally, energization and de-energization of pump 14- may take place automatically and in unison with actuation of valves 13 so as to energize pump 14 only while valves 13 are open. Furthermore, an automatic sequential control may also be used which causes the rotation of the valves 12 and 13 in timed sequence at a predetermined adjustable repetition rate. The valves may also be of any known construction. Thus, it is obvious that the present invention is susceptible of numerous changes and modifications within the scope of a person skilled in the art, and I therefore do not wish to be limited to the details shown and described herein but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

I claim:

1. For a heat exchanger having tubes adapted to be cleaned by receiving cooling water containing cleaning bodies from a cooling water inlet line and discharging water and said cleaning bodies into a cooling water dis charge line, an apparatus for returning said cleaning bodies from said cooling Water discharge line to said cooling water inlet line, comprising:

sleve-type intercepting means operatively connected in said discharge line for intercepting said cleaning bodies, I

means for collecting the thus removed cleaning bodies, and means for intermittently supplying the thus collected cleaning bodies by means of relatively cool Water to said cooling water inlet line,

said last-mentioned means including sluice means,

sieve-type means Within said sluice means, first bypass line means from said intercepting means to said sluice means and from said sluice means back to said discharge line, and second by-pass line means from said inlet line to said sluice means and from said sluice means back to said inlet lines.

2. For a heat exchanger having tubes adapted to be cleaned by receiving cooling Water containing cleaning bodies from a cooling water inlet line and discharging water and said cleaning bodies into a cooling water discharge line, an apparatus for returning said cleaning bodies from said cooling water discharge line to said cooling Water inlet line, comprising:

sieve-type intercepting means operatively connected in said discharge line for intercepting said cleaning bodies,

means for collecting the thus removed cleaning bodies,

and means for intermittently supplying the thus collected cleaning bodies by means of relatively cool water to said cooling water inlet line,

said last-mentioned means including sluice means,

sieve-type means within said sluice means, first bypass line means from said intercepting means to said sluice means and from said sluice means back to said discharge line and second by-pass line means including pump means from said inlet line to said sluice means and from said sluice means back to said inlet lines.

3. For a heat exchanger having tubes adapted to be cleaned by receiving cooling water containing cleaning bodies from a cooling water inlet line and discharging Water and said cleaning bodies into a cooling water discharge line, an apparatus for returning said cleaning bodies from said cooling water discharge line to said cooling water inlet line, comprising:

sieve-type intercepting means operatively connected in said discharge line for intercepting said cleaning bodies,

means for collecting the thus removed cleaning bodies,

and means for intermittently supplying the thus collected cleaning bodies by means of relatively cool water to said cooling water inlet line,

said last-mentioned means including sluice means,

sieve-type means within said sluice means, first bypass line means from said intercepting means to said sluice means and from said sluice means back to said discharge line, and second by-pass line means including pump means from said inlet line to said sluice means and from said sluice means back to said inlet lines,

each of said by-pass line means being provided with adjustable valve means.

4. In a self-cleaning installation for a heat exchanger having tubes adapted to be cleaned by receiving cooling Water containing cleaning bodies from a cooling water inlet line and discharging Water and said cleaning bodies into a cooling water discharge line having interception means for said cleaning bodies, and a connecting line between said inlet and discharge lines,

the improvement essentially consisting of a return system in said connecting line in which said cleaning bodies are collected and are returned to the inlet line by means of relatively cool water including sluice means having means for collecting therein the cleaning bodies, means for conducting the intercepted cleaning bodies from said discharge line to said sluice means including adjustable valve means, and means including further adjustable valve means operatively connecting said sluice means with said inlet line for intermittently supplying the collected cleaning bodies by means of cold water to said inlet line.

5. In a self-cleaning installation for a heat exchanger having tubes adapted to be cleaned by receiving cooling Water containing cleaning bodies from a cooling water inlet line and discharging water and said cleaning bodies into a cooling Water discharge line having interception means for said cleaning bodies, and a connecting line between said inlet and discharge lines,

the improvement essentially consisting of a return system in said connecting line in which said cleaning bodies are collected and are returned to the inlet line by means of relatively cool water including sluice means having means for collecting therein the cleaning bodies, means for conducting the intercepted cleaning bodies from said discharge line to said sluice means including adjustable valve means, and means operatively connecting said sluice means in a circulatory system with said inlet line including pump means for intermittently supplying the collected cleaning bodies by means of cold water withdrawn from the inlet line to said inlet line.

6. In a self-cleaning installation for a heat exchanger having tubes adapted to be cleaned by receiving cooling water containing cleaning bodies from a cooling Water inlet line and discharging water and said cleaning bodies into a cooling water discharge line having interception means for said cleaning bodies, and a connecting line between said inlet and discharge lines,

the improvement essentially consisting of a return system in said connecting line in which said cleaning bodies are collected and are returned to the inlet line by means of relatively cool water including sluice means having means for collecting therein the cleaning bodies, line means for conducting the intercepted cleaning bodies from said discharge line to said sluice means including adjustable valve means disposed in said line means ahead of and behind said sluice means, and further line means operatively connecting said sluice means with said inlet line for intermittently supplying the collected cleaning bodies by means of cold water to said inlet line including further valve means disposed in said further line means ahead of and behind said sluice means.

References Cited by the Examiner UNITED STATES PATENTS 1,562,199 11/25 Baumann -95 X 2,801,824 8/57 Taprogge 165--95 3,021,117 2/62 Taprogge 165-45 X CHARLES SUKALO, Primary Examiner. 

1. FOR A HEAT EXCHANGER HAVING TUBES ADAPTED TO BE CLEANED BY RECEIVING COOLING WATER CONTAINING CLEANING BODIES FROM A COOLING WATER INLET LINE AND DISCHARGING WATER AND SAID CLEANING BODIES INTO A COOLING WATER DISCHARGE LINE, AN APPARATUS FOR RETURNING SAID CLEANING BODIES FROM SAID COOLING WATER DISCHARGE LINE TO SAID COOLING WATER INLET LINE, COMPRISING: SEIVE-TYPE INTERCEPTING MEANS OPERATIVELY CONNECTED IN SAID DISCHARGE LINE FOR INTERCEPTING SAID CLEANING BODIES, MEANS FOR COLLECTING THE THUS REMOVED CLEANING BODIES, AND MEANS FOR INTERMITTENTLY SUPPLYING THE THUS COLLECTED CLEANING BODY BY MEANS OF RELATIVELY COOL WATER TO SAID COOLING WATER INLET LINE, SAID LAST-MENTIONED MEANS INCLUDING SLUICE MEANS, SIEVE-TYPE MEANS WITHIN SAID SLUICE MEANS, FIRST BYPASS LINE MEANS FROM SAID INTERCEPTING MEANS TO SAID SLUICE MEANS AND FROM SAID SLUICE MEANS BACK TO SAID DISCHARGE LINE, AND SECOND BY-PASS LINE MEANS FROM SAID INLET LINE TO SAID SLUICE MEANS AND FROM SAID SLUICE MEANS BACK TO SAID INLET LINES. 